Thursday, October 31, 2019

Visit a railway station, and you are sure to see a porter there. You can easily spot him ina crowd as he wears a red turban and coat, and is seen carrying luggage from one platform to another. He is a very important person at the railway station.

All porters wear a brass badge on their arms. This gives them a licence to carry luggage. If there is too much luggage for a porter to carry, he uses a hand-cart to carry them.

The porter works very hard to make a living. He is not rich and, at times, he and his family have to face many hardships. Since there are many porters at the railway station, they feel lucky when someone asks them to carry their luggage. Sometimes, in spite of working for many days, they still find it difficult to make ends meet.

There are times when some passengers do not pay the correct wages to the porter, but haggle or fight with him.We should realise how hard his job really is, and be kind and thoughtful towards him.So the next time you see his bright, red uniform, remember who he is, and how hard he works!

Thursday, March 7, 2019

#1.If the position of an object does not change as time passes, it is said to be at rest.

#2.If the position of an object changes as time passes, it is said to be in motion. #3.An object can be at rest with respect to one thing and in motion with respect to some other thing at the same time. So motion is not absolute; it is relative.

Tuesday, October 16, 2018

#1.Light travels along straight lines in a medium or in vacuum. The path of light changes only when there is an object in its path or where the medium changes. We call this rectilinear ( straight-line ) propagation of light.

#2.Light that starts from a point A and passes through another point B in the same medium actually passes through all the points on the straight line AB. Such a straight-line path of light is called a ray of light. #3.Light rays start from each point of a source and travel along straight lines till they fall on an object or a surface separating two media (mediums). A bundle of light rays is called a beam of light.#4.A part from vacuum and gases, light can travel through some liquids and solids. A medium in which light can travel freely over large distances is called a transparent medium. Water, glycerine, glass and clear plastics are transparent. #5.A medium in which light cannot travel is called opaque. Wood, metals, bricks,etc.,are opaque. #6.In Materials like oil, light can travel some distance, but its intensity reduces rapidly. Such materials are called translucent.